Display first day of month with TIME and without TIME

-- with time zeroed out
SELECT CAST(DATEADD(DAY,-DAY(GETDATE())+1, CAST(GETDATE() AS DATE)) AS DATETIME)
-- with time as it was
SELECT DATEADD(DAY,-DAY(GETDATE())+1, CAST(GETDATE() AS DATETIME))

FirstDayofMonthWithOutTimePart
2015-03-01 00:00:00.000

FirstDayofMonthWithTimePart
(No column name)
2015-03-01 19:21:48.910